Six teams of scientists have been selected to participate
in the first new mission of NASA's Origins Program, a project
that will seek to answer the questions: Where did we come
from? Are we alone?

Researchers will make their observations with the new
Space Infrared Telescope Facility (SIRTF), now set for launch
in July 2002. The teams will study the formation of galaxies,
stars and planet-forming dust disks with the space-based
telescope.

The teams were chosen from 28 proposals submitted by
astronomers worldwide. They make up the SIRTF Legacy Science
Program, which will involve American-led teams of scientists
from around the world. The six projects comprise more than
3,000 hours of observations, or about half of SIRTF's first
year of operation.

-- Galaxy Birth and Evolution
This project will probe the farthest reaches of the
universe to image the most distant objects that can be
seen by SIRTF and to help answer questions about the
birth and evolution of galaxies to a distance of 12
billion light-years. The project will photograph 0.08
square degrees, or about 1/500,000th of the entire sky.
This area is equivalent to the size of an American
quarter held at a distance of about 1.2 meters (four
feet). Led by Dr. Mark Dickinson of the Space Telescope
Science Institute in Baltimore, Md., this project uses
647 hours of observing time.

-- Black Holes and Galaxies
A companion survey will use both SIRTF infrared cameras
to cover an area of the sky equivalent to about 500 full
Moons, or 100 square degrees of sky. Images produced will
help astronomers study the evolution of dusty galaxies up
to 10 billion light-years from Earth. The survey will
determine whether black holes are the primary energy
source in bright distant galaxies, or whether massive
bursts of star formation can provide the necessary light.
Led by Dr. Carol Lonsdale of the Infrared Processing and
Analysis Center at the California Institute of Technology
in Pasadena, this project uses 851 hours of SIRTF
observing time.

-- Unveiling Hidden Stars
This investigation will study 75 nearby galaxies,
conducting comprehensive imaging to pierce the dust that
hides star formation. This research will yield new
insights into the physical processes connecting star
formation to the interstellar medium of dust and gas that
permeates galaxies. Led by Dr. Robert Kennicutt of the
University of Arizona in Tucson, the project uses 512
hours of SIRTF time.

-- Inside the Milky Way
This large-area survey of the inner portion of our Milky
Way galaxy will produce an invaluable database for the
larger astronomical community. Because the central
regions of our galaxy are heavily obscured by dust, they
remain hidden from optical telescopes. By using SIRTF's
shorter-wavelength infrared camera, this study will lift
the opaque, dusty veil to uncover newly formed stars.
Observations will yield information about the large-scale
structure of the inner Milky Way and uncover details of
the star formation process by observing heavily obscured
clusters of newborn stars. Led by Dr. Ed Churchwell of
the University of Wisconsin at Madison, this
investigation uses 400 hours of observing time.

-- From Gas to Stars
This project will study the process by which stars form
out of giant molecular clouds of gas within our galaxy.
It will concentrate on observing dense and embedded cores
inside molecular clouds located within 100 light-years of
Earth. Its goal will be to follow the history of these
clumps of dust and gas as they contract due to gravity
and evolve into stars. Scientists expect that some of
these newborn stars will have dust disks around them that
will ultimately form planetary systems, like our solar
system. Led by Dr. Neal Evans II of the University of
Texas in Austin, this project uses 400 hours and all
three SIRTF instruments.

-- Planet Formation: When the Dust Settles
A related Legacy Science project will study evolution of
planetary systems from a sample of hundreds of stars up
to 100 million years old. It will study time scales
involved in the planet-building process. While SIRTF
lacks the visual acuity to take pictures of planets
around nearby stars, it will easily detect and
characterize the dusty disks from which planetary bodies
form. This project will yield invaluable information that
could help astronomers understand the formation of our
own solar system. Led by Dr. Michael Meyer of the
University of Arizona in Tucson, the study uses 350 hours
of observing time.

Detailed observational planning for these projects will
be conducted throughout 2001, and the actual observations will
begin a few months after SIRTF is launched.

The SIRTF mission is managed for NASA by the Jet
Propulsion Laboratory in Pasadena. JPL is a division of the
California Institute of Technology. Additional information
about SIRTF and the Legacy Science program is available at
http://sirtf.caltech.edu .